This part is a kind of semiconductor called 1318.

Function of this product has Single 5V RS232/RS422/AppleTalk DCE Transceiver.

Manufacturers : Linear Technology

Image and pinout :

Some of the text within the PDF file :

LTC1318 Single 5V RS232/RS422/AppleTalk® DCE Transceiver FEATURES s s s s DESCRIPTION The LTC®1318 is a single 5V, RS232/RS422 transceiver for connection to the DCE, or peripheral side of an interface link. It includes an on-board charge pump to generate a ± 8V supply which allows true RS232 output swings. The charge pump requires only four external 0.1µF capacitors. The LTC1318 includes two RS232 drivers, a differential RS422 driver, a dedicated RS232 receiver, and a pin selectable RS232/RS422 receiver which can receive either single-ended or differential signals. The LTC1318 features driver outputs which can be taken to common-mode voltages outside the power supply rails without damage. Additionally, the driver outputs assume a high impedance state when the power is shut off, preve [ ... ]

1318 PDF Datasheet Download